19 JUNE Flashcards
is it possible to move voluntarily without somatosensation?
yes of course but it would be terrible!
where does conscious relay happen?
the cerebral cortex
where do divergent pathways happen?
many location in brain stem and cerebrum
what type of pathways are divergent?
BOTH conscious and nonconscious
where does nonconscious relay happen?
the cerebellum
what are high fidelity pathways?
high degree of “body map” locatization
body map = “somatotopic
ie: light touch sensation (conscious relay)
what are the three types of pathways to the brain?
conscious relay
divergent
nonconscious relay
what are the two types of fidelity?
high fidelity
low fidelity
low fidelity:
low degree of “body map” organization
ie: spino-emotional pain (divergent)
what are the two types of neurons in pathways?
projection neurons
interneurons
what modalities are in the conscious relay pathways to the cerebral cortex?
touch
proprioception (conscious component)
pain
temperature
what does the conscious relay pathway use to communicate?
spinal cord tracts
what are the two types of spinal cord tracts?
dorsal columns
anterolateral columns
what do dorsal columns take in?
conscious touch and proprioception
what do anterolateral columns take in?
conscious pain and temperature
discriminative touch is apart of what?
conscious proprioception
what pathway does discriminative touch use?
dorsal column / medial lemniscus pathway
what pathway is the dorsal column / medial lemniscus pathway?
a three neuron pathway
1st order
2nd order
3rd order
break down the three neuron pathway of the dorsal column:
1st order = sensory receptors to the caudal medulla
2nd order = caudal medulla to thalamus
3rd order = thalamus to cerebral cortex (post-central gyrus)
1st order is what?
sensory receptors to caudal medulla
2nd order is
caudal medulla to the thalamus (cross)
3rd order is
thalamus to cerebral cortex (post central gyrus)
ventral horn has what
the spinal level muscle reflex
the lateral column has what?
unconscious proprioception
list the three neuron pathway for discriminative pain and temperature:
1 = free nerve endings to dorsal horn 2 = dorsal horn to thalamus 3 = thalamus to cerebral cortex (post-central gyrus)
where does discriminative pain and temperature take place?
anterolateral column
what pathway is discriminative pain and temperature
spinothalamic pathway (lateral pain system)
what type of fiber is discriminative pain and temperature
a -delta fiber
what type of feelings i discriminative pain and temperature:
“fast” (sharp discriminative) pain and temp
“coarse” touch
divergent is located where?
many locations in the brainstem and cerebrum
divergent is controls what?
emotional and autonomic responses
divergent pathways have how many neuron pathways?
2 or 3 :
- spinoreticular - 2
- spinomesencephalic -2
- spino-emotional - 3
where do divergent pathways take place?
anterolateral column
what type of pain is divergent?
“medial” pain system
what type of neuron is divergent pathway
C fiber - first order neuron
what type of pain is divergent?
“slow” (dull, aching) pain “plus…”
where does the spinoreticular go?
midbrain pons, and medulla:
reticular formation
where does the spinomesencephalic go?
midbrain: periaqueductal gray
where does the spino-emotional go?
thalamus: midline and intralaminar nuclei
the ventral horn has
spinal level muscle reflex
lateral column
unconscious proprioception
incoming a-delta will do what?
SPLIT
the emotional / autonimc response are what?
divergent
if there are two neuron pathways in the emotional/ auonomic pathways that means
the neuron didn’t go to the cebral cortex
if there are thee neurons pathways in teh emotioanl adn autonomic response it means
that the neuron did go to the cerebral cortex
spinoemotional ends where?
the limbic lobe
c fiber belongs where :
emotional and autonomic responses
the a -delta fiber belongs where:
discriminative pain and temperature
what does the spinoemotional do?
regulates emotional and autonomic messages
peripheral sensization
gets lower thresholds for APs in neurons
the spinothalamic pathway has what neuron?
glutamate (fast)
divergent pathway has what neuron?
substance p (slow)
fast pain is what:
superficial "sharp" move away from pain a-delta fiber spinothalamic pathway
slow pain is
deep "dull, aching" rest to recover c fiber divergent pathways
problems with pain occur when:
pain severely limits function
pain persists beyond the time necessary (expected) for tissue healing
the pain matrix def:
structures that process and regulating pain and are capable of creating pain perception in the absence of nociceptive input:
sensory-discriminative aspects occur where?
spinothalamic pathway
motivation-affective aspects occur where?
spino-emotiona, spinoreticular pathways
cognitive-evaluative aspects occur where?
prefrontal lobes of the cerebral cortex
antinociception is
top-down inhibition of pain signals
pronocicpetion is
top-down amplification of pain signals
what are the four states of dorsal horn processing?
normal
supressed
sensitized
reorganized
sensitized dorsal horn processing is
temporary and neuropathic
reorganized dorsal horn processing is
persistent and neuropathic
what are the sites of antinociception?
- periphery
- dorsal horn
- midbrain descending
- hormonal
- amygdala and cortex
chronic pain def:
pain that extends beyond the time expected for normal tissue healing
nociceptive pain is
continuing pain stimulus
pain neurons functioning normally
neuropathic pain is
no continuing pain stimulus
pain neurons typically NOT functioning normally
what is the cause of acute pain?
threat of or actual tissue damage
causes of chronic pain are?
continuing tissue damage
environmental factors (operant conditioning)
sensitization of nociceptive pathway neurons
dysfunction of endogenous pain control system
